U.S. Pat. No. 4,631,780 describes a hand-held skinner for removing strips of skin from animal carcasses comprising an elongate handle including an air motor and having a housing mounted at one end thereof. This hand-held skinner comprises a tooth roll assembly having a pair of substantially identical tooth roll members, each including plurality of teeth which are arranged in circumferentially extending and axially spaced apart rows to thereby define an annular recess between adjacent rows. A threaded output shaft of the air motor is provided for threadedly engaging with a worm gear that is connected to the tooth roll members so when the air motor is energized the shaft and the worm gear mounted thereon will be rotated and thus the tooth roll member.
This hand-held skinner has however several drawbacks, such as that fat and even skin becomes easily accumulated in the recesses and in the space between the two tooth roller members causing blocking of the skinner which thus blocks all subsequent processing steps since the process of releasing the blocking can be time consuming. Moreover, such blocking reduces the lifetime of the motor running the skinner. Also, releasing such blocking by the operator can increases the risk of injuries of the operator but many accidents in the recent years may be attributed to when an operator was trying to release such a blocking. One way of solving the above mentioned blocking problem is by means of implementing more powerful motor, but a more powerful motor is not only heavier but also more costly.
Another disadvantage with this handheld skinner may be linked to the internal arrangement between the cutting blade of the hand-held skinner and the tooth roll assembly causing that too much fat is removed with the skin. The fact that the price of the skin is less than that of the fat leads therefore to a less throughput of this hand-held skinner.
U.S. Pat. No. 4,186,461 discloses a hand held skinner for removing the skin from animal carcasses and comprises a housing having a handle attached thereto. A stationary blade is mounted on the housing closely adjacent a driven revolvable feeder roll assembly, which grips and pulls the animal skin against the blade to permit the skin to be progressively moved from the carcass. Means are provided for driving the roll assembly and this means includes an elongated drive shaft which is journaled in bearings positioned within the housing. The shaft projects through the knife handle and is connected by coupling to an elongated flexible shaft which in turn is connected to a source of power for imparting rotary motion to the flexible shaft. The forward end of the drive shaft is provided with a worm which meshes with a worm gear to drive the latter in a counter-clockwise direction.
Due to how exposed the drive system is there is a high risk that the drive becomes contaminated with tendons and sinews which lower the power of the drive (air motor), with the result that the skin gets stuck in the drive system and the skinner stops and the motor may easily be destroyed. Also, having the drive in the middle result in that the tooth role has less grip because there are no teeth in the middle for gripping the skin, which obviously leads to difficulties in removing the skin. Moreover, when the tooth role hits the product on e.g. the shank bone part, the knife may easily become damaged because there is less support in the middle of the role.